Pneumatic tires are required to make less noise during vehicle running to enhance quietness. Various pneumatic tires have been proposed that reduce vehicle exterior noise such as air column resonance sound generated from the circumferential main grooves formed in the tread surface of the tire, by resonators (Helmholtz-type resonators) each composed of an air chamber and a narrowed groove.
For example, Patent Literature (PTL) 1 proposes a pneumatic tire including: a plurality of rib-shaped land portions; and first and second resonators each composed of an air chamber and a narrowed groove, wherein the number of second resonators located in the vehicle-installed inside rib-shaped land portion is greater than the number of first resonators located in the vehicle-installed outside rib-shaped land portion. Such a pneumatic tire can reduce, at high level, both vehicle interior noise such as road noise and vehicle exterior noise such as pass-by noise resulting from air column resonance sound.